Hydrodynamic torque converters



March 20, 1962, o. K. KELLEY HYDRODYNAMIC TORQUE coNvERTERs 3Sheets-Sheet v1 Original Filed Oct. 3l, 1952 March 20, 1962 Q K, KELLEY3,025,720

HYDRODYNAMIC TORQUE CONVERTERS Original Filed Oct. 3l, 1952 3Sheets-Sheet 2 F F F F v dv) V V(w) u V (w) v (w) v f v (w) @j F F F it?l TLL w u v v v w @u F F F u U U V V I V V (w) u @ff M/-P/YZ' F F w F Fw U ll cau/uma Inventor @ya l'J'z'f//fy en 9L MM@ .Attorneys Mal'Ch 20,1962 o. K. KELLEY 3,025,720

HYDRODYNAMIC TORQUE coNvERTERs Original Filed Oct. 3l, 1952 3Sheets-Sheet 3 1N VENTOR.

TORNEY United States Patent Office h 3,025,720 Patented Mar. 20, 19623,025,720 HYDRODYNAMIC TRQUE CONVERTERS Oliver Kenneth Kelley,Bloomfield Hills, Mich., assignor to General Motors Corporation,Detroit, Mich., a corporation of Delaware Continuation of applicationSer. No. 317,951, Oct. 31, 1952. This application Mar. 26, 1958, Ser.No. 724,204

8 Claims. (Cl. 74-677) This is a continuation `of application Serial No.317,- 951, filed October 31, 1952, for Hydrodynamic Torque Converters,now abandoned, and relates to hydrodynamic torque converters andespecially to such devices adapted to be used in the transmission ofmotor vehicles and in other installations wherein the particularproperties thereof can be advantageously employed.

In my copending application S.N. 194,626, filed November 8, 1950, forDual Range Plural Turbine Gear Drive, now Patent No. 2,766,641 issuedOctober 16, 1956, I have disclosed a torque converter having a pump forcirculating liquid through two turbines, one for starting the mechanismto be driven and the other for the principal driving thereof. Thestarting turbine is connected through gearing, such as a planetaryreduction gear, to the output shaft of the transmission while the secondturbine is connected to the output shaft through a part of the gearingfor rotation with the output shaft. In addition to the two turbines, thesaid copending application discloses two reaction members and asecondary pump member. While the device just described possessesadvantages over the prior art, it is susceptible to improvements,particularly in a simplication of the mechanical structure thereof.

Accordingly, an object of the present invention is to provide animproved torque converter having two turbines in which the constructionmechanically is of the utmost simplicity.

Another object of the invention is to provide a converter, as justdescribed, which possesses better torque multiplication and betterefficiency for given speed ratios.

Other objects, features and advantages of the invention will becomeapparent by reference to the following detailed description of theaccompanying drawings, where- 1n;

FIG. l is a longitudinal section of a form of my invention,

FIG. 2 is a schematic representation of particular blade forms andshapes which have proved satisfactory for the better operation of thedevice,

FIG. 3, 4 and 5 are typical vector diagrams for the operation of theconverter in various phases of such operation, and

FIG. 6 is a section corresponding to FIG. 1 showing a modified form.

Referring now to the drawings and particularly to FIG. l, 10 indicatesthe drive shaft of some prime mover such as an internal combustionengine, which drive shaft has connected thereto a flywheel constructionlll, in turn connected to the multi-part casing 14 and -15 of ahydrodynamic torque converter which drives an output shaft 16 to actuateany desired load in any suitable fashion. In an automotive vehicle thisdrive shaft can either constitute the propeller shaft thereof or can beconnected to drive the propeller shaft. The pump P of the converter isconstructed in part of the arc shaped portion of the housing 14 and hasattached thereto blades 17, to the inner edges of which are secured acore 18. The pump is supported for rotation relative to the output shaft16 by extension 20, which can rotate about a stationary sleeve 21surrounding part of output shaft 16. Radial bearings :19 between theflywheel and pump struc- -ture on the end of the drive shaft 16 permitrelative rotation between these parts.

The first turbine T1 has a core 22, blades 23, and an outer casing orshroud 24 extended axially as shown. This shroud is connected by amember 25 to a ring gear 26 which is supported for rotation by rollerbearings 27 and a thrust bearing 23. Ring gear 26 constitutes thedriving member of a planetary reduction gear which has as the reactionmember thereof a sun gear 29 rotatably supported on a part of outputshaft 16 as shown. A one-way brake, which may be of any suitable type,is interposed between the stationary sleeve 30, splined to sleeve 21,and the sun gear 29, such brake being represnted by the ratchet orlocking rollers 3l which permit the gear to rotate in the direction ofrotation of the pump and which lock the gear to the sleeve whenever thegear attempts to rotate in the opposite direcion. The other part of thereduction gearing comprises a planet carrier 32 having planets 34mounted thereon in mesh both with the ring gear 26 and the sun gear 29.An angular annular extension of`the carrier is splined directly to theoutput shaft as shown.

The second turbine T2 is made up of a core 35, blades 36, and an outermember or shroud 37 which is secured directly to the planet carrier 32,whereby the turbine T2 rotates concurrently with the output shaft 16.

The final converter member comprises a roto-stator or reaction member Rmade up of a core 40, blades 41, and an outer member -or shroud 42,supported for rotation about the stationary sleeve 30 before mentioned.Use is also made of a suitable one-way brake exemplified by ratchetmembers or rollers 44 for permitting rotation of the member R in thedirection of engine rotation but locking this -member against oppositerotation.

The operation of the mechanism just described corresponds closely tothat described in my copending appl-ication, before identified, in thatrotation of the flywheel causes the pump of the converter to rotatetherewith. Liquid circulated by the pump passes first through turbine T1causing it to rotate, as the result of which the ring gear 36 revolvesand applies a driving force to the carrier of the planetary gear system.The sun gear of this system is held stationary by the free-Wheelingbrake, before described, so that rotation of the ring gear causes theplanets to walk around the stationary sun gear carrying the planetcarrier therewith at a reduced rate relative to the speed of rotation ofthe ring gear. Since the planet carrier 4is connected directly to theturbine T2, this turbine must rotate therewith, even though liquidcirculated by the pump may be applying negative torque to the secondturbine. Rotation of the planet carrier of the second turbine causesrotation of the output shaft at a reduced rate of speed relative to thefirst turbine. As the speed of this first turbine increases, :a pointwill be reached at which the first turbine no longer transmits torquebut rotates idly about the planet carrier, causing the sun gear to freewheel or rotate therewith, at which time the second turbine has` assumedthe entire load.

The present invention distinguishes from the disclosure of my priorapplication to a large part in the configuration and angularity of theyblades embodied or mounted in the various elements of the torqueconverter. For example, it has been found that for this particular typeof torque converter improved results can be obtained by shaping theblades of the pump in such fashion that the angle of exit thereof isforward relative to a plane of reference passing through the axis ofrotation of the pump. This forward angle may -be varied within limits,but for purposes of illustration it may be assumed to be in the order offrom 28 to 56. The pump blades have their entrance ends inclinedforwardly with respect to the direction of rotation of the impeller at`au angle of from to 20. This angle is measured on the same basis asthat previously described.

The first turbine T1 has the blades 23 thereof of airfoil shape with anentrance angle of from 0 to 30 backwards, and with an exit angle of from45 to 70 backwards.

The second turbine T2 has the blades 36 thereof also of generallyair-foil shape, with the blades so angularly disposed as to present anentrance angle of approximately 0 to 30 forward and an exit angle offrom 0 to 50 backwards.

The reaction member R has the blades 41 thereof of shape closelycorresponding to the shapeof the blades of the first turbine but of adifferent angular disposition. In the reaction member the blades have anentrance angle of from 0 to 30 forward and a forward exit angle of from40 to 72.

A diagrammatic representation of the various blades and their relativepositions has been shown in FIG. 2, it being understood that the shapeof the blades in each element falls within the range specified for thatparticular element. Due to the shape and angularity of the blades, thevector diagrams of FIGS. 3, 4, and 5 will serve to illustrate thecharacteristics of the present torque converter.

Referring to FIG. 3, the vector diagramsrepresent the condition existingat stall, that is, with the pump rotating but with the other elementsstationary. For the purpose of understanding these diagrams thefollowing symbols are used for indicating the components of velocity ofthe circulating fluid:

F axial co-mponent off velocity W :relative velocity U=velocity of pointon member V= absolute velocity Oil discharged from the pump has an axialcomponent of velocity F, an indicated by the horizontal line so labeled.At thesame time this oil has a relative velocity substantiallytangential to the blade at an angle indicated by the line W. It also hasa velocity in the direction of rotation of the pump coincidental withthe velocity of movement of a point on a pump blade, as indicated by theline U. These components of velocity can be resolved into. anr absolutevvelocity with the angularity indicated by the line V.

The oil discharged from. the pump with this absolute velocity enters thefirst turbine with an axial component substantially identical with thecomponent of discharge from the pump( but, since at stall the iirstturbine is stationary, the relative velocity. and the absolute velocityare identical. The oil passes through the rst turbine and is dischargedtherefrom with an axial component and with a change in direction, sothat the discharge is backwardly with identical relative and absolutevelocities.

The oil continues from the rst turbine into the second turbine with aflow having components of velocity similar of -those of they dischargefrom the first turbine. In passing through the second turbine, however,the direction of flow andthe velocity thereof are changed to such anextent that the oil leaving the second turbine has an axiall componentof velocity and relative velocity to the rear'which coincides with theabsolute velocity.

The oil discharged from thesecond turbine enters the reaction member, orstator, with the same components of velocity, as shown in the diagrambut due to the change in angularity of the blades in this memberrelativeto those ofthe-second turbine the iiow has its direction andvelocity changed as shown again with an axial component F and identicalrelative `and absolute velocities W and V. It will be noted that thedirection of flow now is forwardly instead of backward as is true of theexit from the two turbines. The oil discharged from the stator entersthe pump and, since the pump is moving, the components of velocity arechanged, as shown, with the axial component F being maintained while `arelative velocity W is `again established lalong with a forwardcomponent of velocity U, determined by the rotation of the pump blades.These components can be resolved into the absolute velocity V ofangularity permitting a gradual change as the oil progresses through thepump to :again be discharged therefrom with the absolute velocity firstmentioned.

As the speed of rotation of the pump is increased, the energy of the oildischarged therefrom will become of such magnitude that impingementupon, or contact with, the blades of the first turbine will cause thisturbine to begin rotating. Rotation of the first turbine drives the ringgear 26 and in turn causes rotation of the planets of carrier 32 whichis connected to the load, i.e., to the output shaft i6. The sun gear 29is braked against rotation in a direction opposite to engine rotationand, consequently, it offers such reaction that the planets of thecarrier must walk around the sun gear, carrying the carrier in the samedirection of rotation as the ring gear, but at a reduc-ed speed. Sincethe carrier is connected directly to the second turbine, the secondturbine must rotate therewith, even though oil discharged from the firstpump will enter the second turbine at such an angle and at such velocityas to attempt to establish negative torque in the second turbine. Theangle of discharge of oil from the pump and the Iangularity of theblades of the` first turbine 1are such that suiiicient energy isexpended in the first turbine as to overcome the negative torque in thesecond turbine and the resistance of the load to rotation. In fact, theenergy expended in the first pump is suficient to cause the output shaftto be rota-ted and to drive a vehicle in such manner that accelerationthereof can be accomplished in proportion to increase in engine speed,and hence pump speed. The torque delivered by the pump is multiplied bythe first turbine with an overall exceedingly high efiiciency, eventhough on the surface it would appear that the hydraulic efficiencyof'the first turbine would be low. Such hydraulic ineiiiciency is morethan overcome by the expenditure of energy before mentioned and by theparticular planetary gearing employed.

lt is believed that a considerable part of the energy due to thevelocity and mass of oil discharged by the pump is expended in`actuating the first turbine so that `a relatively smaller part oftheinherent energy is available for establishing negative torque in thesecond turbine.

As the speed of the first turbine, increase-s relative to the speedofthe pump, the torque multiplication decreases and the speed of thesecond turbine likewise increases. This 'condition continues until atmid-range the speed of the first turbine 'approaches synchronism withthe pump. In FIG. 4 vector diagrams showing the condition at midrangeoperation have been presented. The same legends are applied to the linesindicating components of velocity -as were employed in FIG. 3. AnalyzingFIG. 4, it is apparent that, for a given axial velocity F, the oil willhave a relative velocity W and an increased forward velocity component Ugreater than that of FIG. 3, since the pump is rotating at a higherrate. The discharged oil enters the first turbine which isA rotating ata slightly lower rate than the pump, as indicated'by the velocity ofmovement of a point on the first turbine blade, which line U is longerthan the similar line ofthe pump. At this time the first turbine isstill transmitting torque through the planetary gearing to the outputshaft, and likewise the second turbine is also transmitting some torquethrough the gearing to the output shaft. This is due to the oildischarged from the first turbine now at a forward absolute velocitywhich is introduced into the second turbine. The oil discharged from thesecond turbine enters the reaction member which is still stationary, andit acts to return the oil to the inlet of the pump with a forwardvelocity.

The torque transmittedto the output shaft by the first turbine decreasesasV its speed of rotation increases, and at the same time the torquetransmitted by the second turbine increases as its speed of rotationincreases. Ultimately the first turbine attains a speed at which ittransmits no torque and the full torque load is assumed by the secondturbine. At this time the ring gear rotates idly about the carrier and,since there is no reactive force on the sun gear, it rotates with thecarrier. The reaction member R is still stationary, hence multipliedtorque is delivered to the drive shaft through the second turbine T2 andthe carrier 32 rotating therewith. Such torque multiplication continuesuntil the coupling point is reached at which time the relations shown bythe vector diagrams of FIG. 5 arise.

As operation continues, the first turbine will be accelerated to a speedexceeding that of the pump, which condition is graphically illustratedin FIG. 5. Oil discharged by the pump has a higher velocity in thedirection of rotation and, consequently, a sharper absolute velocity inrelation to a given axial component of velocity. When oil enters thefirst turbine, which is now rotating at a faster rate than the pump, ithas a travel through the pump over a longer path, as shown by the linesU, both at entry and at discharge. Therefore, it may be said that theoil discharged from the pump passes through the first turbine with itsforward angle velocity substantially unchanged, and enters the secondturbine at substantially the same absolute velocity as its discharge.Naturally, the first turbine is transmitting no torque and is consuminga relatively negligible amount of the energy o-f the Oil discharged.

The oil entering the second turbine, as before stated, has substantiallythe same absolute velocity as the pump discharge for a given axialcomponent of velocity, but has a different angle of relative velocityand a different velocity in the direction of rotation, as is shown. Thisis due to the fact that the second turbine, in consuming energy from theoil, cannot attain the same speed of rotation as the pump.

In this condition of operation the second turbine is transmittingsubstantially full torque with no torque being transmitted by the firstturbine. It follows that such action by the second turbine imparts driveto the output shaft, and there is no reaction applied to the sun gearwhich is now free to rotate along with the carrier driven by the secondturbine. The first turbine and the ring gear driven thereby can rotateabout the carrier without establishing reaction in the sun gear, so longas the speed of the ring gear does not exceed the speed ,of the carrierin amount sufiicient to tend to move the sun gear in a directionopposite to the engine rotation.

The oil leaving the second turbine in this phase of operation has a verysmall relative velocity in a backward direction, but does have anabsolute velocity in a forward direction which will cause the reactionmember to rotate with the second turbine, a condition possible by theprovision of the free-wheel brake in the mounting of the reactionmember. At this time the converter is performing as a fluid coupling.

If desired, the blade shapes and angles of the various converterelements can be such that the sun gear and the reaction member beginfree wheeling coincidently, and therefore these two parts of themechanism may be permanently joined with a single free-wheel brakeemployed instead of separate brake, as shown in FIG. 6. In thismodification the single one-Way brake having rollers 31 and outer race31a replaces the two brakes having two sets .of rollers 3.1 and 44 ofFIG. 1, otherwise the structure corresponds to that of FIG. 1 as shownby identical reference characters where they occur in the two views. Thevector diagram shown in FIG. 5 shows the condition in the modificationof FIG. 6 at the moment the sun gear and reaction member begin torotate, which necessarily is in unison.

The coupling condition will continue so long as there is no demand fortorque multiplication but, should such demand occur, the increase intorque required to meet the demand will be obtained either by the secondturbine T2 supplying the same, in which event the reaction member R willbecome braked to the stationary sleeve 30; or, if the demand is of avery high nature, then the first turbine T1 will have its speed reducedrelative to the pump P and will also again transmit torque through thereduction gearing to meet the requirement.

From the foregoing it will be seen that the present invention provides atorque converter employing two turbines T1 and T2, the first of whichtransmits high starting torque to the output shaft and the second T2 ofwhich assumes transmission of torque as that transmitted by the firstturbine T1 decreases. The extremely high starting torque transmitted bythe first turbine T1 may be attributed to the shape of the pump blades17 and also to the shape of the blades 23 of the first turbine T1. Aspointed out previously, the pump P has a considerable exit angleforwardly directed, so that the liquid discharged from the pump has anabsolute velocity in a forward direction and at a steep angle relativeto a reference plane passing through the axis of the converter. It willbe noted that the first turbine T1 is so shaped as to have its blades 23inclined generally backwardly so that the liquid discharged from thepump impact with the blades of the first turbine.

It is to be understood that the invention can be modified beyond theillustrated embodiment and, accordingly, any limitations imposed andshown are to be only those set forth in the following claims.

What is claimed is:

1. A hydrodynamic torque converter comprising in combination a pump forcirculating liquid, means for rotating said pump, a first turbine and asecond turbine rotatable by the liquid circulated by said pump, saidpump circulating liquid in a circuit having radial flow zones and axialflow zones, said first turbine being located substantially entirely inan axial fiow zone, an output shaft, means including a planetaryreduction gear unit for establishing a driving connection between saidfirst turbine and said shaft, said first turbine being connected to thedriving member of said unit, said second turbine being connected to thedriven member of said unit and to said shaft for rotation therewith,said pump having the blades thereof so shaped and inclined as todischarge liquid forwardly and at a considerable angle relative to theaxis of the converter, said first turbine having its blades so shapedand inclined that liquid discharged by said pump contacts said turbineblades with high impact to cause said first turbine to transmit highstarting torque through the driven member of said unit to said shaft,and to overcome any negative torque developed by liquid passing throughsaid second turbine, said second turbine having its blades inclined inthe same direction as the blades of said first turbine with theinclination of the blades of said second turbine being substantiallyless than the inclination of the blades of the said first turbine,reactor means for said torque converter, said planetary gear unitincluding a ring gear driving member connected to said first turbine, asun gear, planet pinions rotatably mounted on a carrier connected tosaid second turbine and said output shaft, said planet pinions meshingwith said ring and sun gears, brake means for preventing reverserotation of said reactor means, other brake means for preventing reverserotation of said sun gear, and a spline connection between said otherbrake means and said sun gear.

2. A hydrodynamic torque converter comprising in combination a pump forcirculating liquid, means for rotating said pump, a first turbine and asecond turbine rotable by the liquid circulated by said pump, said pumpcirculating liquid in a circuit having radial flow zones and axial fiowzones, said first turbine being located substantially entirely in anaxial fiow zone, an output shaft, means including a planetary reductiongear unit for establishing a driving connection between saidrst, turbineand said shaft, said first turbine being connected to the driving memberof said unit, said second turbine being connectedA to the driven memberof said unit and to said shaftV for rotation therewith, said pumpVhaving the blades. thereof so shaped and inclined as to discharge liquidforwardly and at a considerableangle relative to the axis of theconverter, said first4r turbine having its blades so; shaped andinclined that liquid discharged bygsaid pump contacts said turbineblades with high impact to cause said first turbine to transmit highstarting torque through the drivenmember of said unit to said shaft, andto overcomeany negative torque developed by liquid passing through saidsecondv turbine, said second turbine having its blades inclined in thesame direction as the blades of said first turbine with the inclinationof the blades of said second turbine being substantially less than theinclination of the blades of the said first turbine, reactor means forsaid torque converter, said planetary gear unit including a driving ringygear connected to said first turbine, asung ear, planet pinionsrotatably mounted on a carrier connected to said second turbine and saidoutput shaft, said planet pinions meshing with said ring and sunA gears,means for preventing reverse rotation of said reactor means, and aspline connection between saidA means for preventing reverse rotation ofthe reactor means and said sun gear for preventing reverse rotationofthe sun gear.

3. A hydrodynamic torque converter comprising in combination a pump forcirculating. liquid, means for rotating said pump, a first turbine and asecond turbine rotatable Aby the liquid circulated by said pump, saidpump circulating. liquid in a circuit having radial flow zones and axialiiow zones, said first turbine being located substantially entirely inan axial flow zone, an output shaft, means including a planetaryreduction gear unit for establishing a driving connection between saidfirst turbine and said shaft, said firstv turbine .being connected tothe driving member of said unit, said second turbine being connected tothe driven member of said unit and to said shaft for rotation therewith,said pump having the blades thereof so shaped and inclined as todischarge liquid forwardly and at a considerable angle relative to theaxis lof the converter, said first turbine having its blades so shapedand inclined that liquid discharged by said pump contacts said turbineblades with high impact to cause said first turbine to transmit highstarting torque through the driven member of said unit to said shaft,and to overcome any negative torque developed by liquid passing throughsaid. second turbine, said second turbine having its blades inclined inthe same direction as the blades of saidk first turbine with theinclination of the blades of said second turbine being substantiallyless than the inclination of the blades of the said first turbine, areaction member for said torque converter, said planetary gear unitincluding a driving ring gear connected tosaid first turbine, a sungear, planet pinions rotatably mounted on a carrier connected to saidsecond turbine and said output shaft, said planet pinions meshing withsaid ring and sun gears, and a single one-way brake for preventingreverse rotation of the reaction member and the sun gear.

4. A hydrodynamic torque converter comprising in combination a pump forcirculating liquid, means for rotating said pump, a first turbine and asecond turbine rotatable by the liquidY circulatedY by said pump, saidpump eirculating liquid in a circuit having radial iiow zones and axialflow Zones, said first turbine being located substantially entirely inan axial flow Zone, an output shaft, means including a planetaryreduction gear unit for establishing a driving connection between saidfirst turbine and said shaft, said first turbine being connected to thedriving member of said unit, said second turbine being connected to thedriven member of said unit and to said shaft for rotation therewith,said pump having the blades thereof so shaped and inclined as todisch-arge liquid` forwardly and at a considerable angle relative to theaxis of the converter, said firstturbin'e havingits blades so shaped andinclined that liquid discharged by said pump contacts said turbineblades with high impact to cause said first turbine to transmit highstarting torque through the driven member of said unit to said shaft,and to over'- come any negative torque developed by liquid passingthrough said second turbine, said second turbine having its bladesinclined in the same direction as the blades of said first turbine withthe inclination of the blades of said second turbine being substantiallyless than the in clination of the blades of the said first turbine, areactor for. said torque converter, said planetary gear unit including adriving ring gear connected to said first turbine, a sun gear, planetpinions rotatably mountedr on a carrier connected to said second turbineand said output shaft,` said planetpinions meshing with said ring andsun gears, a one-way brake having a member secured to the reactor andadapted to rotate only in the sense of rotation of the pump, andintermeshing splines and spline grooves on the sun gear and on saidmember to prevent 4reverse rotation of the sun gear.

5. A hydrodynamic torque converter comprising in combination a pump forcirculating liquid, means for rotating said pump, a first turbine and asecond turbine rotatable by the liquid,V circulated by said pump,saidpump circulating liquid in a circuit having radial flow Zones andaxial flow zones, said firstturbine being located substantially entirelyin an axial ow Zone,an output shaft, means including a planetaryreduction gear unit for establishing a driving connection between saidfirst turbine and said shaft, said first turbine being connected to thedriving member of said unit, said second turbine being connected to thedriven member of said unit and to saidl shaft for rotation therewith,said pump having the blades thereof so shaped and inclined as todischarge liquid forwardly and at a considerable angle relative to theaxis of the converter, said first turbine having its blades so shapedand inclined at predetermined inclination in a range between minimum andmaximum inclination that liquid discharged by said pump contactssaidturbine blades with high impact to cause said first turbine totransmit high starting torque through the driven member of said unit tosaid shaft, and to overcome any negative torque developed by liquidpassing through said second turbine, said second turbinehaving itsblades inclined in the same direction as the blades of said firstturbine at predetermined inclination in a rangebetween minimum andmaximum inclination, the maximum inclination of the range for the bladesof said first turbine being substantially greater than the maximuminclination of the range for the blades of said second turbine, reactormeans for said torque converter, said planetary gear unit including aring gear driving member connected" to said first turbine, a sun gear,planet pinions rotatably mountedon -a carrier connected to said secondturbine and said output shaft, said planet pinions meshing with sa-idyring and'sun gears, brake means for preventing reverse rotation of saidreactor means, other brake meansr for-preventing reverse rotation ofsaid sun gear, and a spline connection between said other brake meansand said sun gear.

6. A hydrodynamic torque converter comprising in cornbination a pump forcirculating liquid, means for rotating said pump, a first turbine and asecond turbine rotatable by the liquid circulated by said pump, saidpump c-irculating liquid in a circuit havingradial flow zones and axialfiow zones, said first turbine being located substantially entirely inan axial flow zone, an output shaft, means including a planetaryreduction gear unit for establishing a driving connection between saidfirst turbine and said shaft, said first turbine being connected to thedriving member of said unit, said second turbine being connected to thedriven member of said unit and lto said shaft for rotation therewith,said pump having the blades thereof so shaped and inclined as todischarge liquid forwardly and at a considerable angle relative to theaxis of the converter, said first turbine having its blades so shapedand inclined `at predetermined inclination in a range between minimumand maximum inclination that liquid discharged by said pump contactssaid turbine blades with high impact to cause said first turbine totransmit high starting torque through the driven member of said unit tosaid shaft, and to overcome any negative torque developed by liquidpassing through said second turbine, said second turbine having itsblades inclined in the same direction as the blades of said firstturbine at predetermined inclination in a range between minimum andmaximum inclination, the maximum inclination of the range for the bladesof said first turbine being substantially greater than the maximuminclination of the range for the blades of said second turbine, reactormeans for said torque converter, said planetary gear unit including adriving ring gear connected to said first turbine, a sun gear, planetpinions rotatably mounted on a carrier connected to said second turbineand said output shaft, said planet pinions meshing with said ring andsun gears, means for preventing reverse rotation of said reactor means,and a spline connection between said means for preventing reverserotation of the reactor means and said sun gear for preventing reverserotation of the sun gear.

7. A hydrodynamic torque converter comprising in combination a pump forcirculating liquid, means for rotating said pump, a first turbine and asecond turbine rotatable by the liquid circulated by said pump, saidpump circulating liquid in a circuit having radial flow zones and aixalflow zones, said first turbine being located substantially entirely inan `axial fiow zone, an output shaft, means including a planetaryreduction gear unit for establishing a driving connection between saidfirst turbine and said shaft, said first turbine being connec-ted to thedriving member of said unit, said second turbine being connected to thedriven member of said unit and to said shaft for rotation therewith,said pump having the blades thereof so shaped and inclined as todischarge liquid forwardly and at a considerable angle relative to theaxis of the converter, said first turbine having its blades so shapedand inclined at predetermined inclination in a range between minimum andmaximum inclination that liquid discharged by said pump contacts saidturbine blades with high impact to cause said first turbine to transmithigh starting torque through the driven member of said unit to saidshaft, and to overcome any negative torque developed by liquid passingthrough said second turbine, said second -turbine having its bladesinclined in the same direction 4as the blades of said first turbine atpredetermined inclination in a range between minimum and maximuminclination, the maximum inclination of the range for the blades of saidfirst turbine being substantially greater than the maximum inclinationof the range for the blades of said second turbine, a reaction memberfor said torque converter, said planetary gear unit including a drivingring gear connected to said first turbine, a sun gear, planet pinionsrotatably mounted on a carrier connected to said second turbine and saidoutput shaft, said planet pinions meshing with said ring and sun gears,and a single one-way brake for preventing reverse rotation of thereaction member and the sun gear.

8. A hydrodynamic torque converter comprising in combination a pump forcirculating liquid, means for rotating said pump, a first turbine and asecond turbine rotatable by the liquid circulated by said pump, saidpump circulating liquid in a circuit having radial flow Zones and axialfiow zones, said first turbine being located substantially entirely inan axial tiow zone, an output shaft, means including a planetaryreduction gear unit for establishing a driving connection between saidfirst turbine and said shaft, said first turbine being connected to thedriving member of said unit, said second turbine being connected to thedriven member of said unit and to said shaft for rotation therewith,said pump having the blades thereof so shaped and inclined as todischarge liquid forwardly and at a considerable angle relative to theaxis of the converter, said first turbine having its blades so shapedand inclined at predetermined inclination in a range between minimum andmaximum inclination that liquid discharged by said pump contacts saidturbine blades with high impact to cause said first turbine to transmithigh starting torque through the driven member of said unit to saidshaft, and to overcome any negative torque developed by liquid passingthrough said second turbine, said second turbine having its bladesinclined in the same direction as the bladesof said first turbine atpredetermined inclination in a range between minimum and maximuminclination, the maximum inclination of the range for the blades of saidfirst turbine being substantially greater than the maximum inclinationof the range for the blades of said second turbine, a reactor for saidtorque converter, said planetary gear unit including a driving ring gearconnected to said first turbine, a sun gear, planet pinions rotatablymounted on a carrier connected to said second turbine and said outputshaft, said planet pinions meshing with said ring and sun gears, aone-way brake having a member secured to the reactor and adapted torotate only in the sense of rotation of the pump, and intermeshingsplines and spline grooves on the sun gear and on said member to preventreverse rotation of the sun gear.

References Cited in the file of this patent UNlTED STATES PATENTS2,293,358 Pollard Aug. 18, 1942 2,382,088 Moffit Aug. 14, 1945 2,616,309Russell Nov. 4, 1952 2,624,215 McRae Jan. 6, 1953

